Tuesday, March 29, 2011

Horizontal Gene Transfer

In the past, it has been widely accepted that “new biological functions, such as antibiotic resistance, in bacteria and other microbes arise primarily through the process of gene duplication within the same organism,” (Treangen, T.J. & Rocha E.P.C., 2011).However, current research suggests that bacteria evolve new abilities primarily by obtaining genes from other bacteria. Bacteria are able to survive in extreme and various environmental conditions because of their ability to quickly modify their genes. According to Treangen and Rocha (2011), this modification of proteins takes place either by “duplication processes followed by slow functional specialization,” in the same way as large, multi-cellular organisms, or by “acquiring different genes directly from other microbes,” also known as horizontal gene transfer.

Recent attempts to simulate the evolution of the genetic code (using the same DNA bases but with different associations of codons and amino acids) through traditional mechanisms were not successful. The code was not shared among all organisms and none of the codes evolved to reach the optimal structure of the actual code (Hunter, 2010). When the scientists simulated horizontal gene transfer of the genetic code, species could successfully exchange genetic material and swap parts of the genetic code and readily discovered the overall optimal structure. This optimal structure became universal among all organisms in the simulation.

While Horizontal Gene Transfer has been studied since 1975, new findings in HGT could change the way scientists view and study biological networks and protein evolution in microbes. It also raises the question of whether eukaryotes evolve in the same way.